/// <summary>
/// 判断数据表中是否存在字段，如果没有，则添加该字段
/// </summary>
/// <param name="tableName">表名</param>
/// <param name="columnName">字段名</param>
/// <param name="dataType">字段类型</param>
/// <remarks>例如:addColumn("news","click","int null")</remarks>
private void addColumn(string tableName,string columnName,string dataType)
{
try
{
string strcmd = "if not exists(select name from syscolumns where id=object_id('" + tableName + "') and name='" + columnName + "') alter table " + tableName + " add " + columnName + " " + dataType;
SqlCommand cmd = new SqlCommand(strcmd, con);
if (con.State == ConnectionState.Closed)
con.Open();
cmd.ExecuteNonQuery();
con.Close();
}
catch (Exception ex)
{
HttpContext.Current.Response.Write(ex.ToString());
}
}
参考链接：http://topic.csdn.net/t/20050727/13/4171312.html
